This application claims the priority of German Patent Document 100 33 781.3, filed in Germany, July 12, 2000, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a double-swirl spraying nozzle having two swirl chambers, which are open toward opposite sides, for generating oppositely exiting spraying jets with an opposite swirl, and having a common inflow duct for the medium to be sprayed.
Double-swirl spraying nozzles of this type are known from German Patent Document DE 197 58 526 A1. These double-swirl spraying nozzles have coaxially arranged swirl chambers with orifices directed in an offset manner. Such swirl spraying nozzles have the purpose of compensating the total swirl exercised by them, so that, if possible, no residual swirl will remain in a medium flowing past the nozzles.
Such nozzles generate the corresponding swirl after a deflection of the fed medium current in each case onto the exterior wall of the swirl space in each case not before the corresponding swirl space half, in which case the swirl space halves can also be separated by a plate with respect to the inflow duct. Both measures clearly restrict the free access cross-section. Also, energy is destroyed in the case of such nozzles with inserted swirl bodies.
It is an object of the present invention to construct a double-swirl spraying nozzle of the initially mentioned type such that the free access cross-section is not limited, without having to fear constructive disadvantages.
For achieving this object, it is provided according to the invention in the case of a double-swirl spraying nozzle of the initially mentioned type that the center axes of the swirl chambers are arranged on different sides of a center plane which extends through the inflow duct and parallel to the swirl chamber axes. As a result of this measure, particularly if the interiors of both swirl spaces are each situated on different sides of the center plane, the medium flows tangentially into the respective swirl chamber so that the velocity generated in the inflow can immediately be changed to a rotation. As a result of the arrangement of the swirl chambers according to the invention, a joint inflow bore can be used without any deflections and without requiring any special measures for generating the swirl. The reason is that, after its entrance, the medium flows in the manner of a free full jet to the opposite wall forming a nose directed against the jet, where it is divided into fractions for the swirl chambers situated side-by-side. As a result of the swirl spaces each offset toward the outside, it also becomes possible to also insert flow breakers into the now formed rearward bottoms, which flow breakers are similar to those of full-cone nozzles with a tangential approach flow, in order to obtain a double full-cone nozzle. As a result of the fact that, despite the large free inflow connection, the two swirl chambers are constructed more or less as separate nozzles, it also becomes possible to change the volume flows and the formation of the jet, including the achievable spraying angle if this should be desired. The new nozzle can therefore not just be used as a swirl compensation nozzle, as described, for example, in German Patent Document DE 197 36 761 A1.
As a further development of preferred embodiments of the invention, it can, in addition to the tangential arrangement of the inflow duct to both swirl chambers, also be provided that the bottoms of the swirl chambers are arranged in a sloped manner with respect to the other partial space. This has the advantage that, when the nozzle is switched off, still present medium can flow from the nozzle. An undesirable clogging or undesirable deposits are therefore avoided. In this case, the inflow duct may also be designed such that its bottom level does not rise from the inlet side to the swirl chamber which is open in the downward direction, so that, when the nozzle is switched off, no liquid remains standing also in the inflow duct. The exterior surfaces of the nozzles can also be constructed such that impacting medium flows off toward the outside. In a particularly simple manner, the swirl chambers in the inflow area of the medium can also be constructed in a mirror-inverted fashion with respect to the center axis of the inflow duct so that a swirl compensation will then also be possible as in the known construction.